Hello. My name is Chris Mitchell. In this introductory module, I will introduce the course and examine the importance of cyber security, a topic that in recent years has become familiar to just about everyone. Hardly a day goes by without news media reporting on the latest cyber attack, whether it's conducted by criminal or government organizations. Cyber security is the name we give to the study of methods we can use to reduce the likelihood of such attacks, however they originate and whatever their motivation. This course is intended to introduce you to the basics of cyber security, what it is, how we can define it, and how we can go about trying to improve the security properties of organizations, as well as our personal lives. We will consider how we might formally define cyber security in the next module. But, for the moment, we can think of it as trying to address any threat deriving from our use of, and dependence on, information and communications technology. If you think about it for a moment, this not only includes using the smart phones, tablets, and desktop computers that we use for work, personal, business, or leisure, but all the aspects of everyday life that depend on the use of information technology. The pervasiveness of information technology means that cyber security issues affect all Internet-connected systems and devices that we use. This includes vehicles for private and public transport, the infrastructure delivering power and water into our homes, and almost every aspect of our working lives, including the operation of factories, transport, and offices worldwide. We depend on information and communications technologies in almost every aspect of our lives, so cyber security has become a fundamental necessity for us all. At the same time, we know that our information processing systems are vulnerable to attack in a huge variety of ways. It is tempting to suggest that the Internet-connected world is the problem, and we should reconsider how we engage with this highly interconnected world. But, in the main, it's impossible to go back, and in reality, we almost certainly don't want to. Modern information and communication technologies bring huge benefits in increasing efficiency, enabling home working, and providing us with many previously undreamt of forms of communication and interpersonal interaction. If we accept that information and communications is here to stay, what are we going to do about the major security threats we all face? In this course, we will introduce some of the techniques that can be used to reduce these threats. It is important to realize that providing security is not just about more and better technology. The ways in which this technology is used, and the skills and knowledge of the people using it, is at least, if not more important. Ultimately, it is all about people. If it wasn't for people, we wouldn't be using the technology that gives rise to the cyber threat. Without involving these same people, we can't hope to achieve the level of cyber security that we wish to have. Finally, we have to be aware that this is a war we will never win. Technology evolves, and so does the cyber threat. We must continue to develop our responses to the threats as they evolve to try to stay one step ahead, or at least not fall too far behind.